Abstract There is an urgent need to engage more low-income smokers in activities that lead to quitting. The current standard of practice for population-level tobacco treatment is phone-based cessation counseling delivered by state tobacco quitlines. But quitline services are restricted to smokers who are ready to quit in the next 30 days, a criterion met by only 20-30% of low-income smokers. Thus, current population level tobacco treatment has nothing to offer 70-80% of low-income U.S. smokers. Based on extensive preliminary research by our study team, we assert that offering a pre-cessation intervention ? Smoke Free Homes ? to low-income smokers who are not yet ready to quit will: (1) engage more smokers in using proven interventions; (2) increase their readiness to quit and quit attempts; (3) reduce the number of cigarettes they smoke per day; and (4) increase cessation. These benefits will accrue in addition to reducing exposure to harmful secondhand smoke for non-smokers in the home. In a Hybrid Type 2 randomized trial, 1,980 low-income smokers from nine states with high smoking prevalence will be recruited from 2-1-1 helplines to receive either current standard practice (Quitline) or expanded services (Quitline + Smoke Free Homes), both delivered by Optum, the largest U.S. quitline service provider. In the latter condition, smokers will be offered cessation counseling first, just like current standard practice, but those who decline will then be offered Smoke Free Homes. At 3-month follow- up, those in the latter condition who accepted quitline services but did not quit will be offered Smoke Free Homes, and those that accepted Smoke Free Homes but did not quit will be offered quitline services. The effectiveness portion of the Hybrid Type 2 design (Aim 1) will use intent-to-treat analyses to compare group differences at 3- and 6-month follow-up in 7- and 30-day point prevalence abstinence with biochemical verification, as well as 24-hour quit attempts and cigarettes smoked per day. The implementation portion of the Hybrid Type 2 design (Aims 2-3) will measure smokers? acceptance and use of the interventions, as well as cost-effectiveness and cost-benefits of adding Smoke Free Homes to quitline services. With rates of smoking and smoking-related cancers much higher in low-income populations and treatment costs exceeding tens of billions of dollars annually in Medicaid alone, this large-scale practical trial will provide strong evidence with high external validity to answer an important policy question : Will changing the standard practice for population-level treatment of smoking result in increased cessation in low-income populations?